Editing Seashell (section)

=== Conchology ===
{{main|Conchology}}

There are numerous popular books and [[field guide]]s on the subject of shell-collecting. Although there are a number of books about land and freshwater mollusks, the majority of popular books emphasize, or focus exclusively on, the shells of marine mollusks. Both the science of studying mollusk shells and the hobby of collecting and classifying them are known as [[conchology]]. The line between professionals and amateur enthusiasts is often not well defined in this subject, because many amateurs have contributed to, and continue to contribute to, conchology and the larger science of [[malacology]]. Many shell collectors belong to "shell clubs" where they can meet others who share their interests. A large number of amateurs collect the shells of marine mollusks, and this is partly because many shells wash up empty on beaches, or live in the [[intertidal]] or sub-tidal zones, and are therefore easily found and preserved without much in the way of specialized equipment or expensive supplies. Some shell collectors find their own material and keep careful records, or buy only "specimen shells", which means shells which have full collecting [[data]]: information including how, when, where, in what habitat, and by whom, the shells were collected. On the other hand, some collectors buy the more widely available commercially imported exotic shells, the majority of which have very little data, or none at all. To [[museum]] scientists, having full collecting data (when, where, and by whom it was collected) with a specimen is far more important than having the shell correctly identified. Some owners of shell collections hope to be able to donate their collection to a major natural history or zoology museum at some point, however, shells with little or no collecting data are usually of no value to science, and are likely not to be accepted by a major museum. Apart from any damage to the shell that may have happened ''before'' it was collected, shells can also suffer damage when they are stored or displayed. For an example of one rather serious kind of damage see [[Byne's disease]].

==== Shell clubs ====
There are a number of clubs or societies which consist of people who are united by a shared interest in shells. In the US, these clubs are more common in southerly coastal areas, such as [[Florida]] and [[California]], where the marine fauna is rich in species.

==== Identification ====
[[File:Concha com pintura (1.2), Acervo do Museu do Colono (Santa Leopoldina).jpg|thumb|A [[Conch shell]], often [[Conch (instrument)|used as a musical instrument]]]]
Seashells are usually identified by consulting general or regional shell-collecting [[field guide]]s, and specific scientific books on different taxa of shell-bearing mollusks ([[monograph]]s) or "iconographies" (limited text – mainly photographs or other illustrations). (For a few titles on this subject in the US, see the list of books at the foot of this article.) Identifications to the species level are generally achieved by examining illustrations and written descriptions, rather than by the use of [[Identification key]]s, as is often the case in identifying plants and other phyla of invertebrates. The construction of functional keys for the identification of the shells of marine mollusks to the species level can be very difficult, because of the great variability within many species and families. The identification of certain individual species is often very difficult, even for a specialist in that particular family. Some species cannot be differentiated on the basis of shell character alone.

Numerous smaller and more obscure mollusk species (see [[micromollusk]]) are yet to be discovered and named. In other words, they have not yet been differentiated from similar species and assigned scientific (binomial) names in articles in journals recognized by the [[International Commission on Zoological Nomenclature]] (ICZN). Large numbers of new species are published in the scientific literature each year. There are currently an estimated 100,000 species of mollusks worldwide.

==== Non-marine "seashells" ====
[[File:Shells01.jpg|thumb|A group of purchased (mostly marine) shells includes the shell of a large tropical land snail (upper right), and a shiny freshwater apple snail shell (center)]]

The term ''seashell'' is also applied loosely to mollusk shells that are not of marine origin, for example by people walking the shores of lakes and rivers using the term for the [[freshwater mollusc|freshwater mollusk]] shells they encounter.  Seashells purchased from tourist shops or dealers may include various freshwater and terrestrial shells as well.  Non-marine items offered may include large and colorful tropical [[snail|land snail]] shells, freshwater [[apple snail]] shells, and pearly freshwater [[unionid mussel]] shells.  This can be confusing to collectors, as non-marine shells are often not included in their reference books.